The present disclosure generally relates to a method of forming a semiconductor structure, and more particularly to a method of releasing a semiconductor structure containing at least one III-V compound semiconductor material from a base substrate.
III-V compound semiconductor materials are a unique group of semiconductor materials which can be used in a wide variety of applications including, for example, optoelectronics, photovoltaics and lighting. III-V compound semiconductor materials are composed of at least one element from Group III metals of the Periodic Table of Elements, i.e., aluminum (Al), gallium (Ga) and indium (In), and at least one element from Group V, e.g., nitrogen (N), phosphorus (P) and arsenic (As), of the Periodic Table of Elements. For example, Group III metals can form arsenide materials, such as GaAs, or phosphide materials such as GaP. GaAs is an III-V compound semiconductor widely used in microwave frequency integrated circuits, light emitting diodes and solar cells. GaP, another Group III-V semiconductor compound, is used in red, orange and green light emitting diodes (LEDs). Group III metals can also form nitrides by reacting with nitrogen. Examples of some common Group III nitrides are AlN, InN, GaN, GaAlN, and GaAlInN. By changing the composition of Al, Ga and/or In within a Group III nitride material, the Group III nitride material can be tuned along the electromagnetic spectrum; mainly from 210 nm to 1770 nm. This spectrum includes the visible LEDs, which are more than a 10 billion dollar industry with a forecasted double digit yearly growth rate. This continuous growth in LED demand enables the infrastructural build-up for the growth and fabrication of III-V compound semiconductor based devices.
Most of consumer-targeted devices based on epitaxial layers of III-V compound semiconductor materials are conventionally grown on sapphire. Some potential applications of these thin film devices have been hampered by the base substrates currently used, whose typical thickness is 100 times as large as that of the thin film devices. If the thin film semiconductor devices alone can be cleaved from the original base substrates and transferred onto other surfaces of arbitrary geometry or flexibility, the thin-film devices based on epitaxial layers of III-V compound semiconductor materials may have a wider field of applications, such as large area flexible displays and general lighting. As such, a method is needed which can be used to cleave epitaxial layers of III-V compound semiconductor materials from original base substrates.